Microscopes with optical zoom systems in the imaging beam path are known. Among them there are, especially, two-channel stereomicroscopes equipped with zoom systems, or single-channel microscopes of, as a rule, higher resolution. The latter are sometimes also known as “macroscopes”, because they provide long working distances and large object fields.
Also known is the use of objectives of variable magnification and variable resolution in multilens microscope systems with or without a tube lens system. Here, object imaging is implemented, for example, by combining the movements of optical components along the optical axis with the variation of the diameter of an iris diaphragm.
In this respect, JP 2007213103 A1 describes an objective with a first fixed and two movable groups and a tube lens arranged behind them. The movement of the two groups along the optical axis is synchronized with the variation of the diameter of a diaphragm arranged behind the fixed group.
The movements of lens components in the zoom systems can be positively controlled by means of cams, e.g., in the form of drum cams, or by means of direct drive units coupled to a lens group each.
Microscopes in which zoom systems are controlled by means of cams are described, e.g., in                U.S. Pat. No. 6,891,669 B2 entitled “Microscope System”,        DE 102 49 177 B4 entitled “Control unit for a microscope”, and        EP 1 510 846 B1 entitled “Guiding system for optical systems, especially zoom systems”.        
Zoom systems controlled by direct drive motors are described, e.g., in                DE 198 22 256 C2 (EP 0 996 863 B1) entitled “Arrangement for the direct control of the motions of a zoom system in a stereomicroscope”,        U.S. Pat. No. 6,590,359 B2 entitled “Method for effecting the synchronous control of several stepping motors”,        U.S. Pat. No. 6,628,098 B2 entitled “Method for accelerating a control movement in a positioner system with step motors”.        
The movement of the lens components by direct motor drive is effected by use of control commands stored in an electronic data record assigned to the respective lens component. The electronic data record has the function of a virtual control cam. As with a mechanical control cam, controlling the movement of a lens component is effected taking into account the movement control of the other movable lens components of one and the same zoom system.
Furthermore, microscopes are known in which motor drives effect not only the movement of the lens components but also the control of diaphragms, e.g., the aperture diaphragm, and of shutters, such as in connection with fluorescence illumination.
Described, e.g., in EP 1 710 610 A3 entitled “Microscope comprising a control unit for controlling the movement speed of the sample stage according to the observation power of the selected lens unit” is a motorized microscope system in which controlling the speed of stage movement for the purpose of focusing is effected as a function of the current magnification of the optical system. The current magnification is derived from the positions of the lens components within a zoom system.
In the publication U.S. Pat. No. 6,891,669 B2 “Microscope System” mentioned above, an arrangement for the active control of optical components is proposed, which takes into account the light intensity detected by a sensor on the image side.
U.S. Pat. No. 7,006,675 B2 entitled “Method and arrangement for controlling analytical and adjustment operations of a microscope and software program” describes an arrangement for the computer-assisted control of system parameters, preferably in a confocal scanning microscope, for the purpose of achieving reproducible setting and control of the parameters for image documentation and image processing.
In US 2003/0103662 A1 “Robotic Microscopy System”, a microscope system with automated parameter settings is described, with which a high throughput of biological samples by fast image analysis is claimed to be achieved.
WO 01/088592 A3 entitled “Microscope Inspection System” describes an automated optical inspection system which is equipped with a zoom autofocus system and a camera. Here again, various functional units of the microscope or external components are coupled via control units.
As an example of prior art, FIG. 1 shows a motorized, modular-design stereomicroscope system, which consists of mechanically coupled and—via interfaces—electronically linked components                for observation, image recording and image processing,        for supporting and focusing,        for illumination and contrasting, and        for operation and control.        
Means for observation, image recording and image processing comprise the binocular viewing tube 1, the motorized zoom system 2 with antiglare shield 3, a controllable multiple nosepiece 7, and the camera 18. A motor focus system with stand column 16 is provided for supporting and focusing. For illumination and contrasting, a transmitted-light illuminator 4 with specimen receptacles 5 and 6 and controllable light source 14, and a reflected-light illuminator with focusing optics 8 and controllable light source 13 are provided. Operation and control are effected by a focus control unit 15, a zoom control unit 17, a transmitted-light operating unit 9, a central control unit 12 for coupling the components to be controlled, a central control element 10 for influencing system control, optional pedal switches 11 for controlling various system functions, and an optional PC 19 with monitor and software for system control and image processing.
Because of the functional coupling of diverse system components, such as e.g., magnification and/or zoom system, focusing system and light source control, a higher functionality of the overall system is achieved, the efficiency of microscopy is enhanced, and setting the system is facilitated for less experienced users.
Known configurations of such microscopes also have means for saving defined system settings in the central control unit or in the PC as user profiles.
As a disadvantage of the known microscopes with functional coupling of diverse system components, including the functional coupling of integrated zoom systems, each motorized or controllable system component is assigned its own, invariable control profile in the form of a mechanical control cam or in the form of an electronic data record as a virtual control cam.
Thus, also the control function for the respective zoom system with direct drive units is preset by the manufacturer and cannot be altered by a central system control facility. There is no possibility of subsequent change.
Also known is the combination of several magnifying components in common, such as, e.g.,                a zoom magnification changing system (also called a microscopical zoom system in the literature) with an objective of fixed focal length,        a zoom magnification changing system with an objective of variable focal length (also known as a zoom objective),        a zoom magnification changing system with a multiple nosepiece for objectives of different, fixed focal lengths,        a zoom magnification changing system with a zoom tube lens system, or        a magnification changer providing discrete magnification steps and provided with a zoom objective and a zoom tube lens system.        